Baugur, owner of House of Fraser, has sold its 31.4% stake in the cash'n'carry operator Booker as it focuses on the retail sector. The Icelandic group's exit raised £100m, in a placing that saw the proportion of institutions' share rise from 23.7% to 43.7%.

The Icelandic bank Kaupthing sold its 6.2%, while its investment fund Kaupthing Capital Partners acquired 22%, agreeing not to sell for a year without the consent of Booker and its adviser Investec.

Tom Hunter's West Coast Capital and HBOS reduced their stakes to help accommodate institutional demand, according to Booker's chief executive, Charles Wilson; he bought 2m shares, taking his holding from 8.1% to 8.3%. The non-executive director Kevin Lyon bought 200,000.

Baugur held its 31.4% stake through its Milton investment vehicle but said it was the right time to sell, three years after being in the consortium that bought Big Food Group, the company behind Booker and the Iceland supermarket chain. Gunnar Sigurdsson, chief executive, said: "Given the exceptional turnaround ... and the fact Booker has now successfully made the transition back to the public markets, now is the right time for us to exit."

Baugur said earlier this year it would sell its media, technology and financial investments for £430m to expand in retail.

Booker, the UK's largest food wholesaler, returned to the stockmarket last year via a reverse takeover by the Aim-listed grocery wholesaler Blueheath. With greater institutional ownership, it now plans to switch to the main market of the London Stock Exchange next year. Shares in Booker closed down 1p, or 4.4%, at 21.75p, valuing the firm at £324.1m.